Since two people came down a county of north Seattle with positive COVID-19 (coronavirus-19) in 2019, the current total cases in the United States (U.S.) are over 12 million . Predicting the pandemic trend under effective variables is crucial to help find a way to control the epidemic . Based on available literature, we propose a validated Vector Autoregression (VAR) time series model to predict the positive COVID-19 cases . A real data prediction for U.S. is provided based on the U.S. coronavirus data . The key message from our study is that the situation of the pandemic will getting worse if there is no effective control.